Feanklin phillips



(No Model.) P. PHILLIPS.

DASH POT FOR STEAM EGINES'.

10.378,105. llaimmel196km,1388.4

lll/ll vlJNITED STATES PATENT OFFICE.

FRANKLINl PHILLIPS, on NEWARK, NEW JERSEY.

oAsI-hPoTFoR STEAM-ENGINEsv SPECIFICATION forming pari; of Letters Patent No. 378,105, dated February 21, 1888.

` Application filed June 27, 1887. Serial No. 242.616. (No model.)

To @ZZ whom, t may concern:

Be it known that I, FRANKLIN PHILLIPS, a citizen of the United States, residing at Newark, Essex county, New Jersey, have invented certain new and useful Improvemenisin Dash- Pots for SteamFngines, fully described and represented in the following specification and the accompanying drawings, forming a part of the same.-

. My invention is adapted for regulating the movements of steam-valves or other mechanical elements whose movement requires arrest at the end of a definite stroke; and the object ments of the latter with perfect certainty.

My device accomplishes these objects in such manner that I am enabled without shock to arrest the movementsof the valve with which the dash-pot is connected, and thus promote the durability of the parts in the most effective manner.

Heretofore the iiuidin the dash-pot cylinder, whether consisting in air or some other gas, has been discharged from the cylinder into the open air after serving its purpose as an elastic cushion.

Myimprovement consists, primarily, in coniining such duid within the receptacle, and thus avoiding the noise produced by the concussion of such fluid when discharged into the air. I effect the confinement of the duid within the cylinder without impairing the functions of the fluid as an elastic cushion by providing the cushion-cylinder with passages adapted to convey the duid from one end of the cylinder to the other during the greater part of the pistons movement, the latter mov ing past the outlet-port to such passage at a suitable distancebefore the end of the stroke to cut off the escape of the iiuid, and thus arrest the piston in the desired manner. In conjunction with such transfer-passages l also employ an independent passage for discharging the duid from the cylinder subsequent to the closing of the transfer-passages, and provide such independent passage with a suitable valve for regulating thedischarge of the duid through such passage into the upper end of the cylinder. Various means may be devised for effecting these objects, one of which is shown in the annexed drawings, in which-,`

Figure'l is a central vertical section of a dash-pot constructed with my improvements, the parts being shown in section where hatched. Fig. 2 is 'an external view of the piston and-sleeve removed from the dash-pot. Fig. 3 is aplan of the piston and sleeve. j Fig. 4' is an external view of the cushion-cylinder with the outer jacket of its shell broken away to show the form' of the ports inthe shell.

Fig. 5 is a plan of the base with its central hub, and Fig. 6 is a plan of the cushion-cylinder with the cover broken away (to show the transfer-passages) at one side of the dotted line fr x.

The construction shown herein is provided, as in many other dash-pots, with an annular piston fitted about a stationary hub, upon the end of which it is pressed by the atmospheric pressure by means of a piston-sleeve, which is litted snugly over 'such hub and provided with a closed head. l

The cushion-cylinder in` my construction is entirely closed at one end and provided atthe other with a cover bored to iit the movable sleeve, and the cylinder and cylinder-headrare shown integral herein, the cylinder being formed with shell a, jacket b, and intermediate passages, c, which, for convenience of construction, are extended entirely through the bottom of the cylinder and closed by contact with a base, d, againstwhich the lower end of .the cylinder is fitted by a ground joint.

From the center of the base is projected the hub d', about which is fitted'the sleeve e, having at its lower end the annular piston e', and passing snugly through the cylinder-heady.

The sleeve is formed with a tight head, c2, provided with lugs g, to which part of a con-y necting-rod, Z, is shown attached in Fig. 1, to connect the piston with a valve-stem in the usual manner. The passages c terminate at their upperends in ports c', and the shell a is perforated near the lower end of th'e cylinder with outlet-ports h, which are inclined to the axis of the cylinder, so as to gradually cut off the escape of the air-beneath the moving piston. Four of the passages o are shown in the drawings, and a corresponding number of ports would be formed4 in connection with such passages. After the passage of the piston over the outlet-ports 71. the tluid is confined in the space between the lowest point of the inclined ports and the bottom of the cylinder, (which is formed by the base (1,) and operates as acushion to arrest the movements of the piston as desired.

As shown in Figs. l and 6, a part of one of the passages c is obstructed by an integral plug, j, through which is formed an independent passage, k, which communicates with the lowest point of the cylinder by avent, 7c'. The passage k is intersected by a valve-plug, m, screwed through the jacket b and provided with a lock-nut, n, to hold it when adjusted. When such valve-plug is turned to partly open the auxiliary passage, the air confined in the lowest part of the cylinder escapes through the vent 7c and passage k into the upper part of the passage c, and thus enters the upper part of the cylinder, as indicated by the arrow z in Fig. l. rlhe head e2 prevents the access of air between the sleeve e and the hub d', and a vacuum is thus produced beneath the head when the piston is lifted by the rod Z, which vacuum operates, as in other dashpots, to accelerate the return of the piston. To preserve such vacuum a check-valve opening outwardly may be applied to the head, as iscommon, and the shell of such a check-valve is indicated at 0 in Fig. l, the internal construction being omitted,but the passage o being shown through the liea'd beneath the shank of the check-valve.

Between the check-valve and the shank a cock, p, is shown to admit air within the sleeve when it is necessary to move the latter freely.

At q is shown a screw-plug for closing an oil-hole in the head e?, and leather packings are shown at o* upon the bottom of the cylinder and at s upon the top of the hub, to soften the concussion if the parts come in contact therewith.

My construction thus involves an annular cylinder closed at one end and having a cylinder-head at the other end bored to receive the movable sleeve which actuates the annular piston, and which is fitted to the hub of the cylinder, shown herein projected from the base d.

The passages c and ports c and h are made of large area relative to the piston e', so as to offer no resistance to the movement of the fluid; and the piston may thus be said to move in equilibrium through the greater part of its stroke in smooth contact with the shell of the cylinder and its central hub, d. The piston is then brought to rest while in continued contact with such parallel surfaces by passing over the inclined outlet-ports and confining the remainder of the fluid within the bottom of the cylinder, from which the iiuid may be vented to graduate the final movement of the piston by the independent passage k and valveplug m.

As the pressure above and below the piston is made substantially equal by the transfer of the fluid through the passages c, it is obvious that the piston can move with less resistance than if its descent were arrested by the partial confinement of the nid in any manner, and the action of the dash-pot is thus rendered exceedingly rapid, while the gradual closing of the ports h arrests the rapid movement of the piston without any shock or the jar occasioned by positive impact.

By closing the annular cylinder with the head f, all dirt and grit are excluded and the device is readily kept in perfect order.

The construction of the head integral with the cylinder and the extension of the annular passages c entirely through the lower end of the cylinder enable me in the most convenient and effective manner to support the cores required to cast such passages between the shell a andjacket Z.

Between the passages c are longitudinal studs t, formed with holes t' to receive bolts u, and the cylinder, when ground to a joint upon the base d, is secured thereto by such bolts, one of which is indicated in Fig. 4 with its head counterbored in the top of the cover and its threaded point projected below the bottom of the cylinder and adapted to fit the tapped holes shown at a in Fig. 1.

Ears zo, provided with holes w', are shown at opposite sides of the base in Fig. 5, to secure it in place where used.

Heretofore means have been provided, as by a ball-joint, to permit the piston to turn in the cylinder without straining the connections of the rod Z,- but I prefer to prevent any tendency to rotation in the piston, and thus main-- tain the joint of the rod Zwith the lugs g in the proper plane.

I provide means for retaining the sleeve in the same relation to the head by forming a longitudinal groove, v, in the sleeve and in the head and snugly fitting a key, v', thereto.

rlhe key or gib is provided with a hooked head at each end, as is common, to retain it in place, as shown in Fig. 1.

I am aware that a connecting-rod and pin such as I have shown would not permit any considerable turning of the piston in the cylinder, if such turning were desired; but my construction is intended to wholly prevent the twisting of the piston and the induction of an abnormal strain or wear upon the rod Z and the pins with which it is connected.

Having thus set forth my invention, what I claim herein is l. In a dash-pot, the combination, with an annular cylinder closed at one end and having at the other end ahead bored to receive a movable sleeve, of an annular piston provided with a sleeve movable through such cover and f1tted to the hub of the annular cylinder, and means for transferring the fluid in the cylinder from one side of the piston to the other, as and `for the purpose set forth.

2. In a dash-pot, the combination, with an annular cylinder closed at one end and having at the other enda head bored to receive a movable sleeve, of an annular piston provided with IOC a sleeve movable through such cover and iitted to the hub of the'annular cylinder, and passages formed in the shell of the cylinder with ports leading into the opposite ends of the cylinder, as and for the purpose set forth.

3. In a dash-pot, the combination, with an annular cylinder closed at one end and having at the other end a head bored to receive a movable sleeve, of an annular piston provided with a sleeve movable through such head and fitted to the hub of the annular cylinder, and passages formed in the shell of the cylinder with ports leading -into the opposite ends of the cylinder, the ports leading into the lower end of the cylinder being inclined, as and for the purpose set forth.

4. In a dash-pot, the combination, with an annular cylinder closed at one end and having at the other end a head bored to receive a movable sleeve, of an annular piston provided with a sleeve movable through such head and tted tothe hub of the annular cylinder, passages formed in the shell of the cylinder With ports leading into the opposite ends of the cylinder, and an independent passage from the bottom of the cylinder to the top with a regulating-valve inserted therein, as and for the purpose set forth.

5. In a dash-potthe combination, with a base having a projecting central hub, of acylindrical shell having longitudinal passages cast therein with ports leading into the upper end of the cylinder, and ports adjacent tothe lower end of the cylinder, an integral head formed with central opening for a sleeve, an` annular piston formed With sleeve tted to such head and to the central hub, and means for securing the cylindrical shell and its integral head to the base, as and for the purpose set forth.-

6. The combination, in a dash-pot having annular cylinder with head bored to receive a sleeve, of a hub fitted within said cylinder, an annular piston tted to the cylinder andhub, the piston-sleeve extended through such head, a longitudinal groove, o, in the sleeve and in the head, and a key, o', fitted thereto, as and for the purpose set forth.

In testimony whereof I have hereunto set m hand in the presence of two subscribing witnesses.

FRANKLIN PHILLIPS.-

Witnesses:

Trios. S. CRANE, L. LEE., 

